Haki
Haki is a mysterious power that has it's origins in Amber. Broadly, there are two types of Haki common to everyone, given the proper training; however, there is a third type that only a certain group of "chosen ones" are said to possess. Types of Haki: Knowledge Haki: Knowledge, also known as Mantra, is a form of Haki that allows the user to sense the presence of others, even if they are concealed from view or too far to see naturally. With enough skill, one can use this Haki to predict an opponent's moves shortly before they make them, thereby making the attack that much easier to evade. This prediction appears to the user as an image or brief "premonition" of what the opponent will do in the user's mind's eye, and the damage the user will take if the attack actually "hits". It appears that the more killing intent the enemy has, the easier they are to predict. Although, more skilled users can predict future moves whether there are ambient murderous intents or not. It varies in strength between users, with Enel's seemingly being the strongest. With his powers, Enel could pick up electromagnetic waves, allowing him to overhear conversations and everything around him; this extended the range of his Mantra to cover roughly a whole planet. By comparison, most of the other users can only keep track of people nearby. Though the power allows the user to predict most attacks, it can be circumvented by various means. It cannot predict inherently random attacks. Tying in with the inability to detect random attacks, Knowledge Haki seems to be linked to the target's own awareness of themselves and their surroundings. It also does not make the user any faster than normal, so the user's ability to dodge is dependent on their speed. It also seems to falter if the user loses their concentration. This type of Haki can also allow the user to sense the emotions and nature of others. Armour Haki: Armour Haki allows the user to create a force similar to an invisible armour around themselves. This allows the user to defend against attacks that would otherwise cause them harm. Only significant physical force can overcome this defense. Naturally this "invisible armour" can be used as a weapon to strike others with. It can be used to augment the user's own attacks, projected ahead of the user as pure brute force, or imbued in weapons to increase their effectiveness. Any attack enhanced by Armour Haki hits immensely harder than it would normally be without it. This type of Haki also has the ability to bypass the powers of all variety, touching the "substantial body" beneath whatever protection the power provides. However, unlike Dark Amber, it does not negate a user's power, allowing them to defend themselves, and continue fighting normally. By the same effect, this Haki can also be used as a higher level of offensive, more so than just bypassing a foe's powers. It can be used to harden parts of one's body, turning the area black, making the user denser and more formidable, and giving their attacks greater power. When a body, body part, or object is hardened, it becomes black and has the same or stronger effect than the invisible application. It is implied that Hardening is stronger than the invisible application as the those who are able to use Hardening are not seen utilising the invisible application. When both Hardened fists clash, it release massive shockwave and black-lighnting like effects. Conqueror's Haki: Conqeuror's Haki is a rare form of Haki that cannot be attained through training and only one in a million people carry it. This type of Haki grants the user the ability to dominate the wills of others. The most common usage so far is knocking those with weak wills unconscious. Whilst inexperienced users are restricted to merely overpowering the will of one individual or blindly knocking out weak-willed people around them, those with more expertise can pick out weak-willed individuals in a large group and knock them out without affecting those around them. However, those with stronger wills can resist or even ignore the effects of Conqueror's Haki. The ability to knock someone out depends on the difference in strength between the person using Haki and the person or persons the user is trying to knock out. The greater the power gap, the easier it is to knock the victim out. According to Rayleigh, while this type of Haki cannot be attained through training, it can be improved through training, as it grows as the user's spirit grows. It seems that upon recovery, victims of Conqueror's Haki experience the sensation of chills running through their body. However, it presumably wears off after a short period.